Light Emitting Diode Package Structure and Manufacturing Method Thereof

ABSTRACT

In one aspect, an LED package structure comprises a fluorescent substrate, a first electrically conductive pattern, a second electrically conductive pattern, at least one electrically conductive element, and an LED chip. The fluorescent substrate has a first surface and a second surface opposite the first surface. The fluorescent substrate comprises a mixture of a fluorescent material and a glass material. The first electrically conductive pattern is disposed on the first surface. The second electrically conductive pattern is disposed on the second surface. The electrically conductive element passes through the fluorescent substrate and connects the first and second electrically conductive patterns. The LED chip is disposed on the second surface and has a light extraction surface that connects the second electrically conductive pattern. The LED chip is electrically coupled to the first electrically conductive pattern via the electrically conductive element.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application claims priority to Taiwan Patent Application No.099133380, entitled “Light Emitting Diode Package Structure andManufacturing Method Thereof”, filed on Sep. 30, 2010, which is hereinincorporated in its entirety by reference.

BACKGROUND

1. Technical Field

The present disclosure relates to a semiconductor package structure anda manufacturing method thereof. More particularly, the presentdisclosure relates to a light emitting diode (LED) package structure anda manufacturing method thereof.

2. Description of Related Art

LEDs generally offer a number of advantageous characteristics such aslong product life, compact size, high shock resistance, low heatgeneration and low power consumption, etc. As a result LEDs are widelyemployed in household applications and as the light source or indicatorof a variety of equipment. Recent developments of new LEDs are in theareas of multiple colors and high brightness. Accordingly, LEDs arefurther employed in applications such as large outdoor bulletin boards,traffic signals and related fields. In the future, LEDs may even becomethe primary light source for illumination that not only conserveelectricity but also are environmentally friendly.

Among the white-light LED package structures commonly adopted in themarket, a type of white-light LED is composed of a blue-light LED chipand yellow phosphor. A prior art manufacturing method of a white-lightLED package structure typically disposes a blue-light LED chip on a baseand wire bonds the blue-light LED chip with the base. Afterwards, usingspin coating, dispensing, spray coating, molding or any other suitableprocess on the base, a yellow fluorescent layer is formed on theblue-light LED chip. A portion of the yellow fluorescent layer emitsyellow light upon excitation by the blue light emitted by the blue-lightLED chip, and in turn the yellow light, combined with the blue lightemitted by the blue-light LED chip, produces white light. However, ayellow fluorescent layer formed by spin coating, dispensing, spraycoating or the like tends to suffer from excessive usage of phosphorpowder and results in uneven thickness of the layer. That is, when theblue light emitted by the blue-light LED chip traverses through a yellowfluorescent layer of a greater thickness, the white-light LED packagestructure may produce a yellowish halo, causing the color of the lightemitted by the LED package structure to be uneven overall.

In order to address the problem associated with uneven spin-coating ofthe fluorescent layer, U.S. Pat. No. 6,395,564 and U.S. PatentPublication No. 2009/261358 disclose a technique that involves sprayingthe fluorescent layer directly on wafers and forming white-light LEDpackage structures after cutting the wafers. However, such prior arttechnique suffers from the problem of lowered scattering efficiencyduring the process of the yellow fluorescent layer emitting yellow lightupon excitation by the blue light. Additionally, as difference inwavelengths may result from crystalline growth on wafers, manufacturingcosts tend to increase if the difference in wavelengths is to berectified by way of spin-coating fluorescent layer on wafers.

In order to address the problem associated with low scatteringefficiency, U.S. Pat. No. 6,630,691 discloses a manufacturing method ofa phosphor layer. Ceramic glass and phosphor are combined under hightemperature to result in a eutectic process that forms a fluorescentsubstrate, which is pasted to LED chips to avoid the issue of lowscattering efficiency and enhance the uniformity of light generated bythe LED package structure. However, as such prior art technique providesno electrode design for the fluorescent substrate, the use of thistechnique is limited to flip chip LED chips.

SUMMARY

The present disclosure provides an LED package structure and amanufacturing method thereof that can help enhance the uniformity in thecolor of light generated by LED chips.

In one aspect, an LED package structure may comprise a fluorescentsubstrate, a first electrically conductive pattern, a secondelectrically conductive pattern, at least one electrically conductivecomponent, and an LED chip. The fluorescent substrate may have a firstsurface and a second surface opposite the first surface. The fluorescentsubstrate may comprise a fluorescent material and a glass material. Thefirst electrically conductive pattern may be disposed on the firstsurface of the fluorescent substrate. The second electrically conductivepattern may be disposed on the second surface of the fluorescentsubstrate. The at least one electrically conductive component mayconnect the first electrically conductive pattern and the secondelectrically conductive pattern. The LED chip may be disposed on thesecond surface of the fluorescent substrate. The LED chip may have alight extraction surface coupled to the second electrically conductivepattern such that the LED chip is electrically coupled to the firstelectrically conductive pattern via the at least one electricallyconductive component.

In one embodiment, a thickness of the fluorescent substrate may beapproximately constant throughout the fluorescent substrate.

In one embodiment, the fluorescent material may comprise yellowphosphor.

In one embodiment, the fluorescent material may comprise phosphors of atleast two different wavelengths.

In one embodiment, the phosphors may comprise at least two of yellowphosphor, red phosphor, and green phosphor.

In one embodiment, the LED package structure may further comprise anunderfill disposed between the light extraction surface of the LED chipand the second surface of the fluorescent substrate, the underfillcovering at least partially the light extraction surface of the LEDchip. In one embodiment, the underfill may cover a plurality of sidesurfaces of the LED chip. In one embodiment, the LED chip may comprise asapphire substrate.

In one embodiment, the LED package structure may further comprise acircuit line substrate where a back surface of the LED chip opposite thelight extraction surface is disposed on the circuit line substrate. Inone embodiment, the LED package structure may further comprise at leastone bonding wire that electrically couples the circuit line substrateand the first electrically conductive pattern.

In another aspect, a manufacturing method of an LED package structuremay comprise: providing a fluorescent substrate having a first surfaceand a second surface opposite the first surface, the fluorescentsubstrate containing therein a plurality of electrically conductivecomponents that connect the first surface and the second surface, thefluorescent substrate comprising a mixture of at least one fluorescentmaterial and a glass material; forming a first electrically conductivepattern on the first surface and a second electrically conductivepattern on the second surface, at least some of the electricallyconductive components connecting the first electrically conductivepattern and the second electrically conductive pattern; and bonding aplurality of LED chips on the second surface of the fluorescentsubstrate, each of the LED chips having a respective light extractionsurface coupled to the second electrically conductive pattern, each ofthe LED chips electrically coupled to the first electrically conductivepattern via a corresponding one of the electrically conductivecomponents.

In one embodiment, the plurality of electrically conductive componentsmay be formed by: forming a plurality of through holes in thefluorescent substrate, the through holes connecting the first surfaceand the second surface; galvanizing the through holes to form aplurality of electrically conductive pillars protruding out of the firstsurface of the fluorescent substrate; milling the electricallyconductive pillars to provide the electrically conductive componentsthat are flush with the first surface of the fluorescent substrate. Inone embodiment, the milling comprises cutting the fluorescent substratewith a cutting device to reduce a thickness of the fluorescent substrateand to expose the electrically conductive components.

In one embodiment, the plurality of electrically conductive componentsmay be formed by: forming a plurality of electrically conductive bumpsin a recess of a carrier base; filling the recess of the carrier basewith the at least one fluorescent material and the glass material, theat least one fluorescent material and the glass material covering theelectrically conductive bumps; heating the electrically conductivebumps, the at least one fluorescent material, and the glass materialtogether to form the fluorescent substrate with the electricallyconductive bumps buried therein; and milling the fluorescent substrateand the electrically conductive bumps to form the electricallyconductive components that are flush with the first surface of thefluorescent substrate.

In one embodiment, the method may further comprise: forming a pluralityof circuit lines on the second surface after forming the secondelectrically conductive pattern, the circuit lines connecting the secondelectrically conductive pattern.

In one embodiment, the method may further comprise: forming an underfillbetween the light extraction surface of the LED chips and the secondsurface of the fluorescent substrate after bonding the LED chips on thesecond surface of the fluorescent substrate, the underfill covering atleast partially the light extraction surface of the LED chips. In oneembodiment, the method may additionally comprise: after forming theunderfill, carrying out a cutting process to form a plurality of LEDpackage structures. In one embodiment, the underfill may cover at leastpartially a plurality of side surfaces of the LED chips. In oneembodiment, the method may also comprise: after forming the underfill,carrying out a cutting process to form a plurality of LED packagestructures.

These and other features, aspects, and advantages of the presentdisclosure will be explained below with reference to the followingfigures. It is to be understood that both the foregoing generaldescription and the following detailed description are by examples, andare intended to provide further explanation of the present disclosure asclaimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the present disclosure, and are incorporated in andconstitute a part of this specification. The drawings illustrateembodiments of the present disclosure and, together with thedescription, serve to explain the principles of the present disclosure.

FIG. 1A illustrates a cross-sectional view of an LED package structurein accordance with an embodiment of the present disclosure.

FIG. 1B illustrates a cross-sectional view of an LED package structurein accordance with another embodiment of the present disclosure.

FIG. 10 illustrates a cross-sectional view of an LED package structurein accordance with yet another embodiment of the present disclosure.

FIG. 2A illustrates a cross-sectional view of an LED package structurein accordance with still another embodiment of the present disclosure.

FIG. 2B illustrates a cross-sectional view of an LED package structurein accordance with a further embodiment of the present disclosure.

FIGS. 3A through 3I illustrate a process of manufacturing an LED packagestructure in accordance with an embodiment of the present disclosure.

FIGS. 4A through 4D illustrate a process of manufacturing of anelectrically conductive component in accordance with an embodiment ofthe present disclosure.

FIGS. 5A through 5D illustrate a process of manufacturing of anelectrically conductive component in accordance with another embodimentof the present disclosure.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1A illustrates a cross-sectional view of an LED package structurein accordance with an embodiment of the present disclosure. Referring toFIG. 1A, in one embodiment, the LED package structure 100 a comprises afluorescent substrate 110, a first electrically conductive pattern 120,a second electrically conductive pattern 130, at least one electricallyconductive component 140 a (only one being representatively illustratedin FIG. 1A), and an LED chip 150.

More specifically, the fluorescent substrate 110 comprises two oppositesurfaces: a first surface 112 and a second surface 114. In oneembodiment, the fluorescent substrate 110 is composed of, for example, amixture of a fluorescent material and a glass material. The fluorescentsubstrate 110 generally has a uniform thickness throughout. The firstelectrically conductive pattern 120 is disposed on the first surface 112of the fluorescent substrate 110. It will be appreciated that, althoughin one embodiment the fluorescent material of the fluorescent substrate110 may be, for example, a yellow fluorescent material, there are othertypes of fluorescent material and fluorescent materials of two or moredifferent colors may be utilized. For example, yellow phosphor and redphosphor may be combined, green phosphor and red phosphor may becombined, and so on. In addition, the second electrically conductivepattern 130 is disposed on the second surface 114 of the fluorescentsubstrate 110. The electrically conductive component 140 a traversesthrough the fluorescent substrate 110, connecting the first electricallyconductive pattern 120 and the second electrically conductive pattern130. The LED chip 150 is disposed on a side of the second surface 114 ofthe fluorescent substrate 110 and has a light extraction surface 152which is connected to the second electrically conductive pattern 130.This allows the LED chip 150 to be electrically coupled to an externalcomponent (not illustrated) via an electrically conductive path formedby the second electrically conductive pattern 130, the electricallyconductive component 140 a, and the first electrically conductivepattern 120. It shall be appreciated that, although the LED chip 150 inone embodiment may be a vertical emission LED chip, other LED chips withequivalent light emission characteristics are also within the scope ofthe present disclosure. For example, high-voltage LED chips oralternating current (AC) LED chips are also applicable.

Noticeably, with the fluorescent substrate 110 electrically coupled tothe LED chip 150 via the electrically conductive component 140 a, theelectrically conductive component 140 a allows a maximized density ofthree-dimensional stacking and minimized dimensions of the LED chip 150.Accordingly, signals between the fluorescent substrate 110 and the LEDchip 150 can be passed through the electrically conductive component 140a, resulting in increased component speed, reduced signal delay, andlower power consumption.

In another embodiment, the LED package structure 110 a further comprisesan underfill 160 a. The underfill 160 a is disposed between the lightextraction surface 152 of the LED chip 150 and the second surface 114 ofthe fluorescent substrate 110. Preferably, the underfill 160 a coversthe light extraction surface 152 of the LED chip 150. In one embodiment,functions of the underfill 160 a include protecting the light extractionsurface 152 of the LED chip 150 and avoiding total reflection of thelight emitted by the LED chip 150 in the gap between the fluorescentsubstrate 110 and the LED chip 150, thereby enhancing the illuminationefficiency of the LED package structure 100 a. In one embodiment, theunderfill 160 a is made of a material that comprises epoxy such as, forexample and not limited to, silicone or silica gel, epoxy resin, or acompound thereof. In other embodiments, the underfill 160 a may furthercomprise a fluorescent material as an additive that is different thanthe fluorescent material in the fluorescent substrate 110. For instance,when the fluorescent substrate 110 comprises a yellow fluorescentmaterial, the fluorescent material of the underfill 160 a may comprisered phosphor. As another example, when the fluorescent substrate 110comprises a green/red fluorescent material, the fluorescent material ofthe underfill 160 a may comprise red phosphor/green phosphor. In thisway, the color saturation of the LED package structure 110 a can beenhanced.

Given that in one embodiment each LED chip 150 is configured to be usedwith the fluorescent substrate 110 that comprises a mixture of afluorescent material and a glass material, that the first electricallyconductive pattern 120, the second electrically conductive pattern 130and the electrically conductive component 140 are disposed on thefluorescent substrate 110, and that each LED chip 150 is a selected onethat generates a desired wavelength, a plurality of such LED chips 150can thus produce light with wavelengths that fall within the same range.Furthermore, as the fluorescent substrate 110 of the LED packagestructure has a uniform thickness, light emitted by the LED chip 150passing through the fluorescent substrate 110 can be converted into alight with high uniformity. A plurality of such LED package structurescan thus produce white light with wavelengths that fall withinapproximately the same range. In other words, the LED package structure110 a according to the present disclosure can produce light with betteruniformity.

In the following description of others embodiments, the same numeralreferences will be used for the same components as described above anddetailed description thereof will not be repeated in the interest ofbrevity as reference can be made to the embodiments described above.

FIG. 1B illustrates a cross-sectional view of an LED package structurein accordance with another embodiment of the present disclosure.Referring to FIGS. 1A and 1B, the LED package structure 100 a′ of FIG.1B and the LED package structure 100 a of FIG. 1A are similar with onemain difference being that in the LED package structure 100 a′ of FIG.1B a plurality of circuit lines 135 are disposed on the second surface114 of the fluorescent substrate 110. In the illustrated embodiment, theLED package structure 100 a′ comprises a plurality of first electricallyconductive patterns 120, a plurality of second electrically conductivepatterns 130, a plurality of electrically conductive components 140, anda plurality of LED chips 150.

In one embodiment, with the circuit lines 135 on the second surface 114of the fluorescent substrate 110, the second electrically conductivepatterns 130 associated with the LED chips 150 are electrically coupledto one another via the circuit lines 135, and a variety of circuitdesigns can be configured depending on the needs. That is, depending onthe needs of a user of the LED package structure 100 a′, there can bedifferent circuit designs configured and implemented on the fluorescentsubstrate 110 to allow the user to efficiently achieve the desiredresults having the LED chips 150 connected in series or in parallel.

FIG. 10 illustrates a cross-sectional view of an LED package structurein accordance with yet another embodiment of the present disclosure.Referring to FIGS. 1B and 1C, the LED package structure 100 a″ of FIG.1C and the LED package structure 100 a′ of FIG. 1B are similar with onemain difference being that the LED package structure 100 a″ of FIG. 1Cfurther comprises a circuit line substrate 170 and at least one bondingwire 180. The actual number of bonding wires 180 is not limited to thatillustrated in FIG. 1C and is determined according to the actual circuitimplemented on the fluorescent substrate 110. The LED package structure100 a″ of the illustrated embodiment is disposed on the circuit linesubstrate 170, and a back surface 154 opposite the light extractionsurface 152 of each of the LED chips 150 is disposed on the circuit linesubstrate 170. The LED package structure 100 a″ is electrically coupledto the first electrically conductive patterns 120 and the circuit linesubstrate 170 via the bonding wires 180. As such, the LED chips 150 canbe electrically coupled to an external circuit (not illustrated) via thecircuit line substrate 170, thereby increasing the applicability of theLED package structure 100 a″.

FIG. 2A illustrates a cross-sectional view of an LED package structurein accordance with still another embodiment of the present disclosure.Referring to FIGS. 2A and 1B, the LED package structure 100 b of FIG. 2Aand the LED package structure 100 a′ of FIG. 1B are similar with onemain difference being that in the LED package structure 100 b of FIG. 2Athe underfill 160 b is extended to at least partially cover a pluralityof side surfaces 156 of the LED chips 150. In the illustratedembodiment, the LED chips 150 may each comprise a sapphire substrate,leakage of light or total reflection can be avoided with the sidesurfaces 156 of the LED chips 150 covered by the underfill 160 a. Thisenhances the illumination efficiency of the LED package structure 100 b.

FIG. 2B illustrates a cross-sectional view of an LED package structurein accordance with a further embodiment of the present disclosure.Referring to FIGS. 2A and 2B, the LED package structure 100 b′ of FIG.2B and the LED package structure 100 b of FIG. 2A are similar with onemain difference being that the LED package structure 100 b′ of FIG. 2Bfurther comprises a circuit line substrate 170 and at least one bondingwire 180 (only two being illustrated in FIG. 2B). A back surface 154opposite the light extraction surface 152 of each of the LED chips 150is disposed on the circuit line substrate 170. The circuit linesubstrate 170 is electrically coupled to the first electricallyconductive patterns 120 via the bonding wires 180. As such, the LEDchips 150 can be electrically coupled to an external circuit (notillustrated) via the circuit line substrate 170, thereby increasing theapplicability of the LED package structure 100 b′.

The above description introduces embodiments of LED package structure100 a, 100 a′, 100 a″, 100 b and 100 b′. The detailed description thatfollows is directed to embodiments of a manufacturing process of an LEDpackage structure in accordance with the present disclosure, using theLED package structure 100 a, 100 a′ of FIGS. 1A and 1B as examples andwith reference to FIGS. 3A-3I, 4A-4D and 5A-5D.

FIGS. 3A through 3I illustrate a process of manufacturing an LED packagestructure in accordance with an embodiment of the present disclosure.FIGS. 4A through 4D illustrate a process of manufacturing of anelectrically conductive component in accordance with an embodiment ofthe present disclosure. FIGS. 5A through 5D illustrate a process ofmanufacturing of an electrically conductive component in accordance withanother embodiment of the present disclosure. For convenience ofillustration and description, carrier base 190 is omitted in FIG. 3D,FIG. 3F is a cross-sectional view along the line I-I in FIG. 3E, andFIGS. 3H and 3I are each a cross-sectional view along the line II-II inFIG. 3G.

Referring to FIG. 3A, according to an embodiment of a manufacturingprocess of an LED package structure, a fluorescent substrate 110 and acarrier base 190 are provided. The carrier base 190 is configured tocarry the fluorescent substrate 110. The fluorescent substrate 110comprises two opposite surfaces: a first surface 112 and a secondsurface 114 (referring to FIG. 3C). In one embodiment, the fluorescentsubstrate 110 is formed by mixing at least one fluorescent material anda glass material under high temperature. Optionally, during thishigh-temperature mixing process protruding structure may be formed onthe fluorescent substrate such as, for example, convex surface, conicalsurface, trapezoidal protrusions or the like, to thereby enhanceefficiency in light extraction and allow designs of angles for lightextraction.

Turning now to FIGS. 3B and 4A, a plurality of through holes 142 areformed in the fluorescent substrate 110 and connect the first surface112 and the second surface 114. In one embodiment, the through holes 142are formed with a machine tool 10 that carries out a laser drillingprocess or a mechanical drilling process on the fluorescent substrate110. Afterwards, referring to FIG. 4B, a galvanization process iscarried out to form a plurality of electrically conductive pillars 144in the through holes 142 and protruding out of the first surface 112 ofthe fluorescent substrate 110. Referring to FIGS. 4C and 4D, a millingprocess is carried out on the fluorescent substrate 110 such that thefluorescent substrate 110 and the electrically conductive pillars 144are milled to result in the first surface 112 with trimmed and flushelectrically conductive components 140 a. Preferably, the millingprocess is carried out through a machine tool 20 such as, for example, adiamond cutter machine, by cutting the fluorescent substrate 110 with adiamond cutter in a clockwise spin direction and by moving the carrierbase 190 that carries the fluorescent substrate 110 in a firstdirection. In other words, when the diamond cutter cuts by spinning thecarrier base moves with respect to the diamond cutter. Of course, thepresent disclosure is not limited to any direction of spin of thediamond cutter or any direction of movement by the carrier base 190 andthe fluorescent substrate 110. For example, in some embodiments thediamond cutter may spin in a counter-clockwise direction.

The machine tool 20 reduces the thickness of the fluorescent substrate110 as well as trims the electrically conductive components 140 a to beflush with the first surface 112. This is beneficial for subsequentsteps of the manufacturing process. As the fluorescent substrate 110 isthinned to a generally uniform thickness throughout, light extractionefficiency of the components can be greatly enhanced. In one embodiment,after thinning the fluorescent substrate 110 has a thicknessapproximately in the range of 10 μm-500 μm. Preferably, the thickness isin the range of 10 μm-150 μm.

In other embodiments, the electrically conductive components may beimplemented in other form factor. Referring to FIG. 5A, a plurality ofelectrically conductive bumps 146 are formed in a recess of the carrierbase 190. The material of the electrically conductive bumps 146 may be,for example but not limited to, gold. Next, referring to FIG. 5B, afluorescent material (not illustrated) and a glass material (notillustrated) are filled in the recess of the carrier base 190. Thefluorescent material and the glass material cover up the electricallyconductive bumps 146. The fluorescent material comprises at least a typeof phosphor. Afterwards, the electrically conductive bumps 146, thefluorescent material and the glass material together are placed underhigh temperature to form the fluorescent substrate 110 with theelectrically conductive bumps 146 buried therein. Lastly, referring toFIGS. 5C and 5D, a milling process is carried out on the fluorescentsubstrate 110 and the electrically conductive bumps 146 to form theelectrically conductive components 140 a that are flush with the firstsurface 112 of the fluorescent substrate 110. The milling process issimilar to that shown in FIGS. 4A-4C and will not be described again inthe interest of brevity. After the machine tool 20 cuts the electricallyconductive bumps 146 and/or the first surface 112 of the fluorescentsubstrate 110, the thickness of the fluorescent substrate 110 is reducedand the electrically conductive components 140 b are flush with thefirst surface 112 of the thinned fluorescent substrate 110. Afterthinning, the fluorescent substrate 110 preferably has a thicknessapproximately in the range of 10 μm-500 μm. Preferably, the thickness isin the range of 10 μm-150 μm.

Noticeably, in the present disclosure, the diamond cutter is spinningwhen cutting the fluorescent substrate 110 and the electricallyconductive pillars 144. The spinning of the diamond cutter allows a verytiny tip of the diamond cutter to turn a cutting point into a cuttingline and eventually a cutting surface with the relative movement betweenthe fluorescent substrate 110 and the diamond cutter. Accordingly, thefirst surface 112 of the fluorescent substrate 110, having been cut bythe diamond cutter, tends to have a rough surface with scale patternsthereon. Consequently, total reflection of the light emitted by the LEDchips 150 (referring to FIG. 1A) can be avoided, and the illuminationefficiency of the LED package structure 100 a (FIGS. 1A) and 100 a′(FIG. 1B) can be enhanced.

Referring to FIGS. 3C and 3D, the first electrically conductive pattern120 is formed on the first surface 112 of the fluorescent substrate 110and the second electrically conductive pattern 130 is formed on thesecond surface 114 of the fluorescent substrate 110. The electricallyconductive components 140 a electrically connect the first electricallyconductive pattern 120 and the second electrically conductive pattern130 (FIG. 3F). Noticeably, after the second electrically conductivepattern 130 is formed, the plurality of circuit lines 135 that connectthe second electrically conductive pattern 130 are formed on the secondsurface 114 of the fluorescent substrate 110. Optionally, a secondelectrically conductive pattern 130 may be electrically coupled to acorresponding second electrically conductive pattern 130 via the circuitlines 135 to form different electrical circuits.

Referring to FIGS. 3E and 3F, a plurality of LED chips 150 are flip chipbonded to the second surface 114 of the fluorescent substrate 110. EachLED chip 150 comprises a light extraction surface 152 that is coupled toa respective first electrically conductive pattern 120. Each LED chip150 is electrically coupled to a respective first electricallyconductive pattern 120 via a corresponding electrically conductivecomponent 140 a. In other embodiments, based on the needs of actualimplementations, the LED chips 150 may be coupled in series or inparallel depending on the design of the electrical circuit formed on thefluorescent substrate 110.

Referring to FIGS. 3G and 3H, an underfill 160 a is formed between thelight extraction surface 152 of the LED chips 150 and the second surface114 of the fluorescent substrate 110. In one embodiment, the underfill160 a covers at least partially the light extraction surface 152 of theLED chips 150.

Referring to FIG. 3H, a cutting process is carried out along a pluralityof cutting lines L to form a plurality of LED package structures suchas, for example, the LED package structures 100 a. At this point themanufacturing process of the LED package structure 100 a is complete.

In another embodiment, referring to FIG. 3I, the underfill 160 b may beextended to cover a plurality of side surfaces 156 of the LED chips 150.When at least some of the LED chips 150 each comprises a sapphiresubstrate, by the underfill 160 b covering the side surfaces 156 of theLED chips 150 total reflection of light emitted by the LED chips 150between a gap between the fluorescent substrate 110 and the LED chips150 can be avoided. This enhances the illumination efficiency of the LEDpackage structure 100 b. Afterwards, a cutting process is carried outalong a plurality of cutting lines L to form a plurality of LED packagestructures such as, for example, the LED package structure 100 a′. Atthis point the manufacturing process of the LED package structure 100 a′is complete.

The manufacturing processes of the LED package structures 100 a, 100 a′as illustrated in FIGS. 3A-3I are for illustrative purpose, and certainsteps described herein may be existing techniques used in the packagingprocess. One ordinarily skilled in the art can adjust, skip or addpossible step(s) depending on the actual needs in implementation.Moreover, the present disclosure is not limited to the forms of the LEDpackage structures 100 a, 100 a′, 100 a″, 100 b and 100 b′. Oneordinarily skilled in the art can use or modify the describedembodiments depending on the actual needs in implementation to achievethe desired technical effect.

In view of the above description, an LED package structure according tothe present disclosure may comprise a fluorescent substrate made from amixture of one or more fluorescent and glass materials, withelectrically conductive patterns and electrically conductive componentsformed thereon. The fluorescent substrate has a generally uniformthickness. The wavelengths produced by the LED chips are approximatelythe same. A light of high uniformity in color can be generated byemitting light from the LED chips through the fluorescent substrate.Consequently, an LED package structure that is capable of emitting whitelight within approximately the same range of wavelengths can beobtained. Relative to prior art method of manufacturing of fluorescentlayers the present disclosure avoids excessive use of fluorescentmaterials, thereby reducing manufacturing costs and enhancing theillumination efficiency of the LED package structure. Additionally, asthe fluorescent substrate is electrically coupled to the LED chips viathe electrically conductive components, signals between the fluorescentsubstrate and the LED chips can be transmitted through the electricallyconductive components. This resultantly increases component speed,reduces signal delay, and lowers power consumption.

Although some embodiments are disclosed above, they are not intended tolimit the scope of the present disclosure. It will be apparent to thoseskilled in the art that various modifications and variations can be madeto the disclosed embodiments of the present disclosure without departingfrom the scope or spirit of the present disclosure. In view of theforegoing, the scope of the present disclosure shall be defined by thefollowing claims and their equivalents.

1. A light emitting diode (LED) package structure, comprising: afluorescent substrate having a first surface and a second surfaceopposite the first surface, the fluorescent substrate comprising afluorescent material and a glass material; a first electricallyconductive pattern disposed on the first surface of the fluorescentsubstrate; a second electrically conductive pattern disposed on thesecond surface of the fluorescent substrate; at least one electricallyconductive component connecting the first electrically conductivepattern and the second electrically conductive pattern; and an LED chipdisposed on the second surface of the fluorescent substrate, the LEDchip having a light extraction surface coupled to the secondelectrically conductive pattern such that the LED chip is electricallycoupled to the first electrically conductive pattern via the at leastone electrically conductive component.
 2. The LED package structure ofclaim 1, wherein a thickness of the fluorescent substrate isapproximately constant throughout the fluorescent substrate.
 3. The LEDpackage structure of claim 1, wherein the fluorescent material comprisesyellow phosphor.
 4. The LED package structure of claim 1, wherein thefluorescent material comprises phosphors of at least two differentwavelengths.
 5. The LED package structure of claim 4, wherein thephosphors comprise at least two of yellow phosphor, red phosphor, andgreen phosphor.
 6. The LED package structure of claim 1, furthercomprising an underfill disposed between the light extraction surface ofthe LED chip and the second surface of the fluorescent substrate, theunderfill covering at least partially the light extraction surface ofthe LED chip.
 7. The LED package structure of claim 6, wherein theunderfill covers a plurality of side surfaces of the LED chip.
 8. TheLED package structure of claim 7, wherein the LED chip comprises asapphire substrate.
 9. The LED package structure of claim 1, furthercomprising a circuit line substrate, a back surface of the LED chipopposite the light extraction surface disposed on the circuit linesubstrate.
 10. The LED package structure of claim 9, further comprisingat least one bonding wire that electrically couples the circuit linesubstrate and the first electrically conductive pattern.
 11. Amanufacturing method of a light emitting diode (LED) package structure,the method comprising: providing a fluorescent substrate having a firstsurface and a second surface opposite the first surface, the fluorescentsubstrate containing therein a plurality of electrically conductivecomponents that connect the first surface and the second surface, thefluorescent substrate comprising a mixture of at least one fluorescentmaterial and a glass material; forming a first electrically conductivepattern on the first surface and a second electrically conductivepattern on the second surface, at least some of the electricallyconductive components connecting the first electrically conductivepattern and the second electrically conductive pattern; and bonding aplurality of LED chips on the second surface of the fluorescentsubstrate, each of the LED chips having a respective light extractionsurface coupled to the second electrically conductive pattern, each ofthe LED chips electrically coupled to the first electrically conductivepattern via a corresponding one of the electrically conductivecomponents.
 12. The method of claim 11, wherein the plurality ofelectrically conductive components are formed by: forming a plurality ofthrough holes in the fluorescent substrate, the through holes connectingthe first surface and the second surface; galvanizing the through holesto form a plurality of electrically conductive pillars protruding out ofthe first surface of the fluorescent substrate; milling the electricallyconductive pillars to provide the electrically conductive componentsthat are flush with the first surface of the fluorescent substrate. 13.The method of claim 12, wherein the milling comprises cutting thefluorescent substrate with a cutting device to reduce a thickness of thefluorescent substrate and to expose the electrically conductivecomponents.
 14. The method of claim 11, wherein the plurality ofelectrically conductive components are formed by: forming a plurality ofelectrically conductive bumps in a recess of a carrier base; filling therecess of the carrier base with the at least one fluorescent materialand the glass material, the at least one fluorescent material and theglass material covering the electrically conductive bumps; heating theelectrically conductive bumps, the at least one fluorescent material,and the glass material together to form the fluorescent substrate withthe electrically conductive bumps buried therein; and milling thefluorescent substrate and the electrically conductive bumps to form theelectrically conductive components that are flush with the first surfaceof the fluorescent substrate.
 15. The method of claim 11, furthercomprising: forming a plurality of circuit lines on the second surfaceafter forming the second electrically conductive pattern, the circuitlines connecting the second electrically conductive pattern.
 16. Themethod of claim 11, further comprising: forming an underfill between thelight extraction surface of the LED chips and the second surface of thefluorescent substrate after bonding the LED chips on the second surfaceof the fluorescent substrate, the underfill covering at least partiallythe light extraction surface of the LED chips.
 17. The method of claim16, further comprising: after forming the underfill, carrying out acutting process to form a plurality of LED package structures.
 18. Themethod of claim 16, wherein the underfill covers at least partially aplurality of side surfaces of the LED chips.
 19. The method of claim 18,further comprising: after forming the underfill, carrying out a cuttingprocess to form a plurality of LED package structures.